The semiconductor integrated circuit (IC) industry has experienced rapid growth. Between and during operation processes of manufacturing semiconductor wafers, chemical mechanical polishing (CMP) process has been used to remove unwanted material from semiconductor wafer surfaces.
A CMP apparatus includes a pad for polishing the semiconductor wafer. The pad and the semiconductor wafer are both rotated when in contact with each other. The roughness of the surface of the pad, the rotation speeds of the semiconductor wafer and the pad, and the relative pressure between the semiconductor wafer and the pad are factors that affect the polishing result, i.e., the planarization of the semiconductor wafer.
During the CMP process, the pad itself becomes smoother from the polishing. Therefore, it is necessary to have a reconditioning process to recreate the rough pad surface. CMP apparatus have pad conditioners to recondition the pads. The conditioner resurfaces the pad, removes the used slurry, and supplies the pad surface with fresh slurry. Ways to maintain the polish rate and uniformity is sought to improve the post CMP wafer quality.